How do I find User Preferences in 2.8?
User preferences for 2.8 are now under the Edit > Preferences menu, to the right of File menu.



Saving and loading of settings has been moved into the Preferences window and is now done from a dedicated popup dialog, at the bottom left of the panel.



Autosave is on by default, meaning that any changes should be saved automatically on (gracious) exit. If Auto Save is disabled, a save button is made visible and settings are only saved at user discretion (good for testing with keymaps and other hard to reverse or critical settings).